The present embodiments relates to transducer arrays. In particular, the elements of an ultrasound transducer are formed from a substrate.
The substrate is a piezoelectric ceramic. The substrate is diced into multiple elements. The gaps or kerfs between separated elements are filled to form a composite, such as a 1-3 composite.
One example dicing technique is a dicing saw. A blade cuts the substrate. However, the blade dicing may be slow and result in elements with large kerfs and chipping at the dicing edges. The minimum kerf width is about 15 micrometers. Large kerfs reduce the active area for transduction, which reduces sensitivity.
Another example dicing technique is deep reactive ion etching (DRIE). In DRIE, coating with a seed layer, coating with a photo resist, patterning, electroplating to form an etching mask, and deep reactive ion etching are performed. However, DRIE is process intensive and expensive. The thickness of the substrate may be limited due to the etching angle.